A/C problems solved, plus good news for those with older KJs

FreedomKJ · **Posted:** Fri Jul 08, 2005 1:35 pm

I posted this on the ezboard yesterday, but it appears that the general discussion section is already gone so I figured I'd better post it here.

Anyway, I posted about a week or two ago that occasionally while driving the A/C would change from coming out the dash vents and only come out from the defrost and floor, no matter what I set the controls to. I took the KJ in to the dealer and they found that the control head had gone bad. It was replaced and the problem appears to be gone.

What's the good news for owners of older KJs? Well remember when the first pics of the new '05 KJs came out everyone commented about Jeep finally adding a button to turn the compressor on or off, no matter what the vent setting was? Well when I picked up my KJ after the service it had the new control head that the '05s have. This means if you have the desire you can replace yours with the new one and it should work just fine. According to the service sheet the exact part number is 55037533-AE. On thing I noticed though is that the compressor still runs when the vent is set to defrost, whether the compressor button is on or off.

I remember a few others mentioned having the same problem, what did your dealers say?

corwyyn · **Posted:** Fri Jul 08, 2005 1:53 pm

My understanding of the a/c running in defrost mode is that the a/c de-humidifies the air and allows the system to clear fogged windows faster. I have had several vehicles with this feature and it does seem to work. Just my 2 cents. Nice to hear about being able to swap out the control heads

bennybmn · **Posted:** Fri Jul 08, 2005 5:36 pm

Yeah the AC does de-humidify the air, but sometimes it's so humid and cold out, that the AC on the windshield actually fogs the OUTSIDE of the windshield, forcing me to flip on the wipers, which then chatter because most of the windshield is try... Sometimes hot air is good, ya know? Good to know they smartened up tho!! Always seemed funny that the control knob had twice as many settings as it needed!! Just having an on-off button would have saved some space on the dial, ya know?

JJsTJ · **Posted:** Sat Jul 09, 2005 10:29 am

Hmmm...my warranty is almost up, maybe I should milk them for an upgrade since mine has always done the same thing. Do you know if there is a TSB covering the fix? It might reference it on your work order.

FreedomKJ · **Posted:** Tue Jul 12, 2005 6:22 pm

JJsKJ wrote:

Hmmm...my warranty is almost up, maybe I should milk them for an upgrade since mine has always done the same thing. Do you know if there is a TSB covering the fix? It might reference it on your work order.

No TSB listed, sorry!

Loopkey · **Posted:** Wed Oct 12, 2005 11:33 am

Was any of the wiring changed? I just tried to install the control module from a 2006 KJ and the only thing that did not work was the AC switch.

Jeepjeepster · **Posted:** Wed Oct 12, 2005 1:09 pm

wonder what that head unit would cost if i just wanted to buy it?

Loopkey · **Posted:** Wed Oct 12, 2005 4:26 pm

Jeepjeepster wrote:

wonder what that head unit would cost if i just wanted to buy it?

~$50 CAD from the dealer.

My 2002 is in the shop so they gave me a 2006 to drive. I asked the parts manager about the price of the head unit, and he was curious to see if it would work. So we went out to the parking lot to swap the head units. The only thing that didn't work was the A/C compressor button. From my 2002 service manual, it says the compressor is controlled by the vacuum lines attached to the selector knob. From FreedomKJ's post he put a head unit from a 2005 in a 2003 and it worked. I don't know if the system changed from 2002 to 2003 or if the difference is between 2005 and 2006 or if the swap requires a wiring change?

EDIT: I am going to pull the unit out and check the part number tonight to see there is a difference between 2005 and 2006.

Edwin · **Posted:** Wed Oct 12, 2005 7:31 pm

corwyyn wrote:

My understanding of the a/c running in defrost mode is that the a/c de-humidifies the air and allows the system to clear fogged windows faster. I have had several vehicles with this feature and it does seem to work. Just my 2 cents. Nice to hear about being able to swap out the control heads

That's exactly right! :wink:

billforde · **Posted:** Wed Oct 12, 2005 7:47 pm

02limited wrote:

Jeepjeepster wrote:

wonder what that head unit would cost if i just wanted to buy it?

~$50 CAD from the dealer.

My 2002 is in the shop so they gave me a 2006 to drive. I asked the parts manager about the price of the head unit, and he was curious to see if it would work. So we went out to the parking lot to swap the head units. The only thing that didn't work was the A/C compressor button. From my 2002 service manual, it says the compressor is controlled by the vacuum lines attached to the selector knob. From FreedomKJ's post he put a head unit from a 2005 in a 2003 and it worked. I don't know if the system changed from 2002 to 2003 or if the difference is between 2005 and 2006 or if the swap requires a wiring change?

EDIT: I am going to pull the unit out and check the part number tonight to see there is a difference between 2005 and 2006.

I got a 2005 unit for my 2004 for $28+shipping US. Worked perfectly.

Loopkey · **Posted:** Wed Oct 12, 2005 9:46 pm

I checked the part number from the 2006 Liberty Sport and it is P55037533-AG (REV_A 18-MAY-05).

I pulled the following image from my 2002 service manual under section 24 - A/C Heater Control. It shows connector 3 as "REAR WINDOW DEFOGGER SWITCH AND TEMPERATURE BLEND DOOR- CONNECTOR B (12 PIN)". For the people with service manuals for the 2003 or 2004 are there any differences?

roadrunner · **Posted:** Thu Oct 13, 2005 1:26 am

More on the subject...

http://www.jeepkj.com/forums/viewtopic.php?t=1002

http://www.jeepkj.com/forums/viewtopic.php?t=1265

http://65.42.106.152/forums/showthread. ... ost5416807

A/C problems solved, plus good news for those with older KJs

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